The present invention is broadly concerned with cofferdams for use in temporarily holding back a body of water when performing construction, repairs or bank stabilization in the bed of a river or a lake or any body of water, and also on dry land for flood protection. Such cofferdams are typically constructed of a framework of individual frame structures placed in adjacent alignment along a portion of the body of water which is to be held back. A flexible waterproof fabric is secured along the framework for holding back the water so that work may be performed in the area behind the framework. Given the substantial hydrostatic pressure created in holding back a large volume of water, the frame structures must be extremely sturdy. They are typically formed of steel or iron stock and have a triangular configuration which is best suited for bearing the pressure load. These cofferdams are constructed so that they may be quickly erected and disassembled. Portable dams of this type are well known to those having skill in the art.
Because of the need for quick assembly and disassembly of the portable dam, it is critical that the individual frame structures be configured not only for ease in erecting, but also ease and efficiency in transporting. Frequently, portable dams must be erected as quickly as possible, especially during emergency conditions, so it is important that the individual frame structures be connected in a manner to permit this. Current modes of connection include clamps which must be bolted directly to the frame structures, and stakes which must be driven into the ground as well as bolted to the frame structure. A substantial amount of time is invested in bolting on these clamps. Additionally, because of the large number of individual frame structures required in constructing a length of cofferdam, it is desirable to maximize the number of frame structures that can be stacked on a truck or trailer that transports the frame structures. Generally, individual frame structures are integral pieces and are fixed in their triangular configuration, which is not particularly conducive to efficient stacking. Accordingly, several truck load trips must usually be made to bring a sufficient number of frame structures to the cofferdam construction site.
A further problem faced by erectors of portable cofferdams lies in being able to place the framework down in a stable position in the bed of the body of water to be held back. There is a tremendous pressure placed on the frame structures from the body of water that is held back. Frequently, the river bed is uneven or rocky, which creates stability problems by causing the continuity of the framework to be disrupted. Weak points in the framework caused by such a disruption could allow the cofferdam to collapse, leading to disastrous results.
Accordingly, there is a need in the art for frame structures for use in a portable dam that are adapted for quick assembly and disassembly in erecting the dam with minimal amount of set up time or expenditure of manpower. Additionally, it is desirable that such frame structures be configured for efficient transportation and storage.
Further, there is a need for frame structures of a portable dam that provide stabilization for supporting large hydrostatic pressures and that are adapted to adjust to uneven terrain on which the dam is erected so that stability of the dam can be maintained.
The invention provides for frame structures for forming a framework used in temporary portable cofferdams. The frame structures are aligned and connected adjacently to each other to form the framework for supporting the waterproof fabric material which holds back the water.
It is an object of the invention to provide a frame structure for use with a portable dam wherein said frame structure is capable of quick assembly and disassembly for ease in erection, transportation and storage. The frame structure is comprised of a support beam, a base beam and at least one brace beam. The connection of the beams is configured to impart a triangular shape to the frame structure, with the support beam being disposed at an angle transverse to the vertical plane of the water which is to be dammed, the base beam being disposed horizontally and lying essentially parallel to the bed of the body of water, and the brace beam having one end connected to the base beam and the other end being connected to the support beam for providing support thereto. The beams are removably connected to each other in a pivoting relationship such that the beams can be swung down to lie parallel to each other into a folded arrangement.
It is another object of the invention to provide coupling members for quickly connecting and disconnecting adjacent frame structures when constructing and disassembling the portable dam framework. The coupling members comprise an elongated bar having ring openings at both ends which are adapted to receive the ends of the beams of the frame structures. This allows workers to quickly place and secure frame structures in adjacent alignment merely by placing the coupling members over the beam ends of the frame structures. The coupling member maintains the adjacent frame structures in a fixed, spaced-apart relationship without the need for clamps requiring bolting.
It is a further object of the invention to permit the joining of a plurality of frame structures rigidly together to form a pre-fabricated portable dam frame section which can be erected as a unit prior to placement in the water to increase the efficiency in building the entire dam. A number of frame structures are adapted to be fixedly held together as a section through the use of one or more stiffening members so they may lifted and placed as a unit in the water. This helps decrease the time spent in the water in erecting the portable dam and makes the overall operation more efficient.
It is a further object of the invention to provide a foot assembly for portable dam frame structures which provide a stable support for the frame structure on the bed of the water body being dammed. The foot assembly allows the weight placed on the frame structure to be distributed along its point of contact with the ground surface, and prevents the frame structure from sinking too deeply into soft bottom beds. The foot assembly is comprised of one or more flat, planar base support members. Each foot support member has a bracket for receiving the frame structure. The foot support members are adjustable and can be moved along the bottom of the frame structure as needed to achieve stability.
The above features are objects of this invention. Further objects will appear in the detailed description which follows and will be otherwise apparent to those skilled in the art.
For purpose of illustration of this invention preferred embodiments are shown and described hereinbelow in the accompanying drawing. It is to be understood that this is for the purpose of example only and that the invention is not limited thereto.